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Main Area => General GS500 Discussion => Topic started by: Egaeus on February 25, 2007, 09:42:19 AM

Title: Carb "experts": what does this thing do?
Post by: Egaeus on February 25, 2007, 09:42:19 AM
In the carb bowl there is a thin "tube" that sticks down.  The float has an L-shaped tube sealed with an o-ring that goes over it.  What is the purpose of that thing?  I can't even theorize as to what it does.  I searched, but searching doesn't turn much up when you don't know what it's called. :)
Title: Re: Carb "experts": what does this thing do?
Post by: Jughead on February 25, 2007, 10:57:46 AM
It's the Over Flow.
Title: Re: Carb "experts": what does this thing do?
Post by: Egaeus on February 25, 2007, 11:59:15 AM
Quote from: Jughead on February 25, 2007, 10:57:46 AM
It's the Over Flow.
It can't be the overflow.  It's the reason my bike wasn't running right.  That, and there's no reason for the overflow to have an o-ring. 
Title: Re: Carb "experts": what does this thing do?
Post by: Jughead on February 25, 2007, 12:47:52 PM
Oh Sticking own Instead of Sticking Up towards the Carb Body.OK OK........ it's the...... I have no Clue. :laugh:

Likemy Neighbor Dumb A$$ Neighbor asks me all of the time when I work on Something."Is that the Orifuss Valve?" I always Say "Dumba$$ Do you even know what an Orfice Valve is?"
Title: Re: Carb "experts": what does this thing do?
Post by: starwalt on February 25, 2007, 01:07:46 PM
Are you referring to the plastic tube with the O-ring that is part of the float assembly?

If you are referring to the plastic tube with the O-ring, this is part of the "Starter System" as referenced by the OEM Suz manual. Fuel is pulled up the plastic tube at the angle cut and up into the brass loop that runs outside the main carb body. The fuel is then in the area that the choke linkage moves and enters the carb throat and the intake of the engine.

In short, that's where the gas comes from for the Choke setting.

If we are talking about the same gadget.
Title: Re: Carb "experts": what does this thing do?
Post by: baco99 on February 25, 2007, 03:31:37 PM
when are we supposed to pull the choke open?  the manual says to start the bike cold with the choke closed; which seems counter-intuitive to me. 
Title: Re: Carb "experts": what does this thing do?
Post by: Wrecent_Wryder on February 25, 2007, 04:46:42 PM
[4
Title: Re: Carb "experts": what does this thing do?
Post by: Gisser on February 25, 2007, 05:46:09 PM
Quote from: Wrecent_Wryder on February 25, 2007, 04:46:42 PM
Stumbling over semantics, I think. A true choke (which ours isn't) is a butterfly valve over the carb throat that you "pull" closed, not "pull open". So, yeah, you'd close it to start the engine cold.

Although conventional wisdom says different, the GSTwin choke actually works pretty much like any other choke when all is said and done.  In this case, the butterfly valve is the throttle plate, the closed throttle creates a vacuum, the choke lever opens up a bypass circuit and an extra rich air/fuel mix is drawn in.   As the throttle (or butterfly valve) opens, manifold vacuum decreases and the choke effect disappears--no matter that the choke lever is still in on position.     :cheers:   
Title: Re: Carb "experts": what does this thing do?
Post by: baco99 on February 25, 2007, 09:33:15 PM
so then why is it that when the bike is running, and the choke lever is pulled forward, creating the bypass, the bike stalls?  too much gas and not enough air? or is my choke not working...?
Title: Re: Carb "experts": what does this thing do?
Post by: Gisser on February 26, 2007, 01:45:02 AM
Quote from: baco99 on February 25, 2007, 09:33:15 PM
so then why is it that when the bike is running, and the choke lever is pulled forward, creating the bypass, the bike stalls?  too much gas and not enough air? or is my choke not working...?

Idling?  Cruising?  The choke has no effect at highway speed.  Mine don't.  Try it.   8)
Title: Re: Carb "experts": what does this thing do?
Post by: baco99 on February 26, 2007, 06:54:05 AM
idling.  when the bike is idling, and you pull the choke level towards you, the engine accelerates for a second and then starts to die. 

never tried it while at speed.
Title: Re: Carb "experts": what does this thing do?
Post by: starwalt on February 26, 2007, 08:35:25 AM
Quote from: baco99 on February 26, 2007, 06:54:05 AM
idling.  when the bike is idling, and you pull the choke level towards you, the engine accelerates for a second and then starts to die.
My latest 90 also does this after it warms up. In general - and we have discussed this in some other threads - this is an indication that a cleaning is due for the carbs. The engine is dying due to fuel starvation. My manifestation is a very large change in RPM when stopping to idle and a slight addition of the choke lever.

In short - go through the carbs and clean them.
Title: Re: Carb "experts": what does this thing do?
Post by: Egaeus on February 26, 2007, 08:45:19 AM
Back on-topic, how is that the choke?  The orifice that's attached to the carb body is too small to put a wire from a brass wire brush through it.  I just stuck my compressor's blow gun on it and hoped for the best.  That, and my choke worked.  How is that possible when the orifice in the carb float was completely blocked on one carb, and almost completely blocked on the other.  And why did it affect the running of my bike, even when the choke was off?

Title: Re: Carb "experts": what does this thing do?
Post by: The Buddha on February 26, 2007, 12:26:52 PM
Show me a pic. Or [oint out a number in the parts schematic in bike bandit or somehting.
Cool.
Srinath.
Title: Re: Carb "experts": what does this thing do?
Post by: Egaeus on February 26, 2007, 12:32:33 PM
It's not in the parts schematic.  There is an o-ring on the float.  That o-ring "seals" the part I'm talking about. 
Title: Re: Carb "experts": what does this thing do?
Post by: The Buddha on February 26, 2007, 12:58:51 PM
Quote from: Egaeus on February 26, 2007, 12:32:33 PM
It's not in the parts schematic.  There is an o-ring on the float.  That o-ring "seals" the part I'm talking about. 

Oh I get it ... I will check it tonight and tell you. I think it just holds the floats up ... though the bowls being bolted in really are what hold it up. it just holds it up when float bowls are off.
Cool.
Srinath.
Title: Re: Carb "experts": what does this thing do?
Post by: starwalt on February 26, 2007, 03:41:08 PM
Ok, I couldn't stand it anymore...here's an image of a carb (upside down) showing what I think you are talking about.  Click on it for a bigger/better picture.
(http://vtxstar.com/sitebuilderImages/Carbs/float_upside_down_anote_thb.JPG) (http://vtxstar.com/sitebuilderImages/Carbs/float_upside_down_anote.JPG)

IF it is what you asking about, see my first post in this thread about the "Starter System" better known as the Choke.
Title: Re: Carb "experts": what does this thing do?
Post by: Egaeus on February 26, 2007, 09:34:43 PM
That's it, but I still don't see how that narrow opening can pull enough fuel to affect starting, how it affected the normal running of my bike, and how my choke still worked when the hole at the end of the L on the float was completely clogged.
Title: Re: Carb "experts": what does this thing do?
Post by: boltiker on February 26, 2007, 10:53:10 PM
Just a suggestion. A bad o-ring seal of the L-shaped part may increase fuel flow and make the bike run "better".
Title: Re: Carb "experts": what does this thing do?
Post by: Gisser on February 27, 2007, 02:11:10 AM
Quote from: Egaeus on February 26, 2007, 09:34:43 PM
That's it, but I still don't see how that narrow opening can pull enough fuel to affect starting, how it affected the normal running of my bike, and how my choke still worked when the hole at the end of the L on the float was completely clogged.

But your observation was that the clogged choke was not the cause of your problem.  Synchronizing the carbs was the apparent solution:  http://gstwins.com/gsboard/index.php?topic=33403.msg372824#msg372824 

:dunno_white:

Title: Re: Carb "experts": what does this thing do?
Post by: starwalt on February 27, 2007, 07:38:10 AM
Quote from: Egaeus on February 26, 2007, 09:34:43 PM
That's it, but I still don't see how that narrow opening can pull enough fuel to affect starting, how it affected the normal running of my bike, and how my choke still worked when the hole at the end of the L on the float was completely clogged.
To find out what the OEM manual says about these parts of the carb, click on the image below...
(http://vtxstar.com/sitebuilderImages/Carbs/Choke_OEM_thb.JPG) (http://vtxstar.com/sitebuilderImages/Carbs/Choke_OEM.JPG)
Title: Re: Carb "experts": what does this thing do?
Post by: Egaeus on February 27, 2007, 07:59:59 AM
I synchronized the carbs before I started any of this.  It didn't do anything.  In my email to tussey when he asked about my bike, I said that they needed to be synchronized, because that's what was causing the problem, but it didn't help.

Synchronizing the carbs also wouldn't affect the fact that when I ran on one cylinder at a time, the problem still occurred in the left cylinder. 
Title: Re: Carb "experts": what does this thing do?
Post by: Gisser on February 27, 2007, 02:42:16 PM
Quote from: Egaeus on February 27, 2007, 07:59:59 AM
I synchronized the carbs before I started any of this.  It didn't do anything.  In my email to tussey when he asked about my bike, I said that they needed to be synchronized, because that's what was causing the problem, but it didn't help.

I don't doubt that, but that's not the chain of events that you yourself report in this post:  http://gstwins.com/gsboard/index.php?topic=33403.msg372824#msg372824

:icon_rolleyes:
Title: Re: Carb "experts": what does this thing do?
Post by: Egaeus on February 27, 2007, 02:49:57 PM
I balanced the carbs, it didn't work.  I checked the spark plugs, they were white.  I check the fuel flow, it seemed sufficient.  I made videos, and posted my **HELP** thread.  I balanced the carbs 3 times total while trying to find this problem. 
Title: Re: Carb "experts": what does this thing do?
Post by: Egaeus on March 07, 2007, 08:45:35 PM
Starwalt, thank god you were right.  I was hurting my brain trying to figure out what I did to fix it.  It is the choke, and it didn't fix the problem.  Whatever it was, it's back.  It ran fine for a few minutes, but it was short-lived.
Title: Re: Carb "experts": what does this thing do?
Post by: johnlaughland on March 08, 2007, 06:46:16 AM
er... I've posted some info on your original thread....